SELENIUM - two different toners & DANGEROUS
Damir Tiljak
> .... so then Jean-David Beyer said ...
>
> > I strongly suggest not mixing your own selenium toners from
> > selenium powder as the powdered selenium is easier to ingest and is
> > said to be much more dangerous than the prepared solutions.
>
> This may be a good time to mention that the prepared solutions
> are dangerous as well.
>
> I just got back to darkroom work after many years out of it, and
> paid the price for not being careful. I've never used gloves or
> tongs with developer / stop / or fix, and never had a bad reaction.
> I knew I had used selenium toner as well those many years ago, and
> for some reason I just assumed it was fairly benign if you just
> rinsed or dried your hands. Yes, I read the warning label. No, I
> didn't take it too seriously.
> I used my bare hands to handle the prints in the toner one evening,
> and I'm sure I rinsed them in water each time I did so. However,
> that doesn't guarantee that a small splash won't stay on your skin
> a while, or that you won't absent-mindedly touch hand to mouth at
> the wrong time. Anyway ... I must have ingested a small amount
> of solution or absorbed it through the skin, because I spent the
> entire next day feeling AWFUL! -- a definite "poisoned" feeling,
> and plenty of vomiting long after there was anything left in my
> stomach.
> Now I use tongs, rinse my hands even if they're dry, and wash them
> thoroughly at the end of a darkroom session.
>
> If the label on a chemical has a warning, take it seriously. I
> probably ingested a tiny amount of working solution 1+31 and paid
> an awful price for being careless.
>
> Dennis
I suppose that this posting is due to my question about preparing
toner from pure selenium. I know selenium is poison - but I just
don't have source of prepared solution - Kodak don't sell selenium
toner in Croatia -if I want to have it I must prepare it myself -
that's the reason why I ask about active substance in toner - so
that I can buy active substance and dissolve it in water.
It seems that I will answer to that question myself - in the meantime
I finally find book with complete chemistry of photography.
It seems that active substance in commertial selenium toner is
sodium selenite:
Na Se
2
in prepared toner active substance is different, when toner is prepared
from sodium sulphide active substance is sodium selenosulphide:
Na SeS
2
this kind of toner require bleaching before toning,
due to presence of sodium sulphide which also act as a sepia toner
tone is different from tone when print is toned in toner
prepared from sodium sulphite in which active substance is
sodium seleno-sulphate:
Na SSeO
2 3
Just as sodium thiosulphate is obttained by dissolving sulphur in hot
soluion of sulphite so seleno-sulphate is obtained by dissolving
selenium
in hot sulphite solution.
This is theory, practice is obviously different - I prepared toner by
boiling selenium with sodium sulphite but this toner don't work.
I don't know what I did wrong, I will try again but this time with
sodium sulphide. I will appreciate advice from someone who prepared
selenium
toner at home.
As I never had or saw Kodak selenium toner I shall be pleased if someone
can post text from label on the bottle, also to describe solution - what
is
the colour, how it smells like?
Let me know if anybody want to know what is going on in print during
toning.
Damir
Jean-David Beyer
Damir Tiljak wrote (in part):
[lengthy postings about dangers of mixing your own selenium toner,
and dangers of careless use, snipped]
> I suppose that this posting is due to my question about preparing
> toner from pure selenium. I know selenium is poison - but I just
> don't have source of prepared solution - Kodak don't sell selenium
> toner in Croatia -if I want to have it I must prepare it myself -
> that's the reason why I ask about active substance in toner - so
> that I can buy active substance and dissolve it in water.
[snip]
> Just as sodium thiosulphate is obttained by dissolving sulphur in hot
> soluion of sulphite so seleno-sulphate is obtained by dissolving
> selenium
> in hot sulphite solution.
>
I would advise starting out with sodium selenite if it is an article
of commerce.
> This is theory, practice is obviously different - I prepared toner by
> boiling selenium with sodium sulphite but this toner don't work.
It may have worked perfectly. The results vary mainly with the kind of
photographic paper you used, and a little depending on the developer you
used. It also depends on the concentration of the toner.
With some papers, such as Ilford Galerie and Kodak Elite, I see none or
almost no change in color. What does happen is that the density of the
darkest parts of the prints increase slightly. This is sometimes very
useful. But I use 1 part of Kodak's toner to about 20 parts of water as
I usually do not want a color change. Toning in selenium is also said to
increase the resistance of the print to degradation from gasses such as
sulfur dioxide and hydrogen sulfide in the air.
You may have used the toner at too weak a concentration for obvious
color change, or you did not use it long enough. Kodak recommend using
their toner at a concentration of 1 part toner to 3 parts water for about
5 minutes.
> I don't know what I did wrong, I will try again but this time with
> sodium sulphide. I will appreciate advice from someone who prepared
> selenium
> toner at home.
I never tried it. I would worry that sodium sulfide might cause other
problems, if not with the print that you are trying to tone, then with
fogging other materials in the darkroom.
>
> As I never had or saw Kodak selenium toner I shall be pleased if someone
> can post text from label on the bottle, also to describe solution - what
> is
> the colour, how it smells like?
The concentrate looks a lot like water and smells a little like ammonium
hydroxide (but not as strong).
The MSDS data sheet reveals its composition as follows:
Sodium selenite 1-5%
Water 50-55%
Ammonium thiosulfate 25-30%
Sodium sulfite 5-10%
This is the mixing order, and starting points for the formula.
> Let me know if anybody want to know what is going on in print during
> toning.
>
> Damir
--
Jean-David Beyer
Shrewsbury, New Jersey
Wlodek Witek
> It may have worked perfectly. The results vary mainly with the kind of
> photographic paper you used, and a little depending on the developer you
> used. It also depends on the concentration of the toner.
toning of my prints if I want a total purple/brown tonality. I notice that
my prints (Record Rapid and Agfa Multicontrast Classic dev. in Neutol)
first respond by gainig density in dark areas, then slowly take a brown
tonality moving from dark to light areas. My dillutions are rather thin
1:20 or so. This dillution gives me time for final decission when I look
at tyheprint: can just deepen the blacks (cooler tonality results), do a
split toning or full toning.
> I usually do not want a color change. Toning in selenium is also said to
> increase the resistance of the print to degradation from gasses such as
> sulfur dioxide and hydrogen sulfide in the air.
This is true, however a sulfide (like Kodaks two-bath Sepia Toner) toner
is now proved to be far more effective then selenium toning (and cheaper
then gold-toning).
> > Let me know if anybody want to know what is going on in print during
> > toning.
As far as I know a thin layer of selenium is deposited arround the silver
grains. The size of the particle has influence on the RI (Reflective
Index) and therefore the hue of the image.
Wlodek Witek
--
Wlodek Witek
paper and photoconservator
University of Oslo Library
Norway
mac...@www.bsmx.com
I sent to Damir two selenium toner formulas: Kodak's T-55 and T-56.
I am not going to post them to the group just in case anyone tryes to sue
me because of selenium's "dangerous nature". If someone else want's the
formulas I will send them by private e-mail. Cheers!
Francisco Garcia Maceda
mac...@www.bsmx.com
PD. I can asure you nobody would be alive without selenium in their bodies.
Michael Gudzinowicz
Damir Tiljak <damir....@zg.tel.hr> writes:
>I suppose that this posting is due to my question about preparing
>toner from pure selenium. I know selenium is poison - but I just
>don't have source of prepared solution - Kodak don't sell selenium
>toner in Croatia -if I want to have it I must prepare it myself -
>that's the reason why I ask about active substance in toner - so
>that I can buy active substance and dissolve it in water.
The MSDS for EKC's Rapid Selenium Toner lists the following ingredients:
SODIUM SELENITE 1-5 %
WATER 55-60 %
AMMONIUM THIOSULFATE 25-30 %
SODIUM SULFITE 5-10 %
An old edition of the Focal Encyclopedia of Photography has the procedure
to make a direct selenium toner:
1) Dissolve 100 g sodium sulfite in just enough water to get it into
solution.
2) Add 10 g finely powdered elemental selenium.
3) Add water to make 1 liter. (I'd let it stand overnight in a sealed
bottle at this point.)
4) Decant or filter the clear portion of the solution.
The toner is used undiluted - wash the print first to remove most of the
hypo.
To get warm tones on bromide papers, they suggest bleaching with a
solution used for sepia toning - one version is:
750 ml warm water
50 g sodium or potassium ferricyanide (not ferro)
10 g potassium bromide
20 g sodium carbonate monohydrate
water to make 1 liter
(you can probably leave the carbonate out)
The prints should be completely washed before bleaching, or silver
density will be reduced.
After bleaching, prints are rinsed/washed, and developed in the selenium
toner which has been diluted 1 + 3 parts water.
Any red stains may be removed with a 10 % bisulfite solution.
>It seems that I will answer to that question myself - in the meantime
>I finally find book with complete chemistry of photography.
>It seems that active substance in commertial selenium toner is
>sodium selenite:
Selenite is Na2SeO3
>Na Se
> 2
Na2Se is sodium selenide.
>in prepared toner active substance is different, when toner is prepared
>from sodium sulphide active substance is sodium selenosulphide:
>
>Na SeS
> 2
>
>this kind of toner require bleaching before toning,
>due to presence of sodium sulphide which also act as a sepia toner
>tone is different from tone when print is toned in toner
>prepared from sodium sulphite in which active substance is
>sodium seleno-sulphate:
>
>Na SSeO
> 2 3
Na2 Se SO3 - it's formed from selenium (Se8) and sulfite, much like the
reaction of sulfite with elemental sulfur to form sodium thiosulfate
(hypo - Na2SSO3).
>Just as sodium thiosulphate is obttained by dissolving sulphur in hot
>soluion of sulphite so seleno-sulphate is obtained by dissolving
>selenium in hot sulphite solution.
Try to avoid heating the solution, and use a well ventilated area if you
must (outdoors, with the toner downwind).
>This is theory, practice is obviously different - I prepared toner by
>boiling selenium with sodium sulphite but this toner don't work.
>I don't know what I did wrong, I will try again but this time with
>sodium sulphide. I will appreciate advice from someone who prepared
>selnium toner at home.
I don't why it didn't work, but perhaps the concetrations weren't
correct, or the sulfite was oxidized to sulfate by boiling, and sulfate
would be ineffective. The article which I cited was written by Ira B.
Current, who is quite reliable.
>As I never had or saw Kodak selenium toner I shall be pleased if someone
>can post text from label on the bottle, also to describe solution - what
>is the colour, how it smells like?
The MSDS information which is at the beginning of this reply, simply
gives some concentration ranges. Be careful when if you try to mix your
version of Kodak's toner. I'd dissolve the sulfite first, then the
selenite, and slowly add the ammonium thiosulfate. Thiosulfate in acidic
solutions will reduce selenite to red elemental selenium, which is one
reason to wash the print firat to remove acid fixer. Also, the Kodak
toner is used at anywhere from 1 + 3 to 1 + 39 dilutions, often diluted
with hypoclear. I used 2% Kodalk as the diluent (1 part toner + 19 parts
2 % Kodalk solution) which doesn't permit selenite reduction. The
solution is quite stable, and can be stored for months in a sealed glass
container. The toner smells like ammonia which is volitile. At basic
pHs, there isn't any real generation of SO2 or SeO2 gas fron sulfite or
selenite. After toning, rinse the prints, treat with hypoclear, and wash
well since they have been exposed to alkaline hypo in the toner.
>Let me know if anybody want to know what is going on in print during
>toning.
Some texts indicate that silver selenide is formed, which is reasonable
with the bleach/redevelopment method but has been proposed with little
evidence in the texts, for the direct toner. One guess is that elemental
selenium is plated on the silver, and/or silver is oxidized, while
selenium is reduced to selenide. In acidic solutions selenite is reduced
by hypo to selenium - one might speculate the silver may catalyze the
process in the toner, though I haven't seen any evidence for that.
Good luck, and don't drink the toner, inhale powdered selenium or get the
stuff in your eyes. I'd be careful with the home made toners which
contain much higher selenium concentrations than dilute Rapid toner, and
they don't have their toxicity well defined.